2018年5月23日 · Diatoms belong to the taxonomic phylum Bacillariophyta. There are approximately 10, 000 known diatom species. Of all algae phyla, diatom species are the most numerous. Diatoms frustules are used to differentiate species. Diatom frustules are composed of very pure hydrated silica within a layer of organic, carbon containing material.

2018年5月18日 · Most diatoms are unicellular, but some are colonial or filamentous. Most are photosynthetic, but some species lack chlorophyll and live heterotrophically among decaying marine algae. Pennate (i.e. bilaterally symmetrical) diatoms occur in both freshwater and marine habitats; centric diatoms (i.e. radially symmetrical) occur predominantly as ...

2018年6月11日 · Bacillariophyta A phylum of algae comprising the diatoms. These marine or freshwater unicellular organisms have cell walls (frustules) composed of pectin impregnated with silica and consisting of two halves, one overlapping the other. Diatoms are found in huge numbers in plankton and are important in the food chains of seas and rivers.

2018年6月11日 · dinoflagellates A division (Dinoflagellata) of protists that are heterotrophs but closely allied to brown algae and diatoms (they are sometimes classified as algae). Many have brown or yellow chromoplasts containing xanthophyll and chlorophylls a and c; others are colourless. Typically, dinoflagellates have two flagella, one propelling water to ...

diatomaceous earth (kieselguhr) Deposit composed of fossil diatoms (see BACILLARIOPHYCEAE), which is mined for many industrial uses: as a mild abrasive in metal polishes, as a filtering medium (e.g. in sugar refineries), for insulation of boilers and blast furnaces, etc., and under the name ‘kieselguhr’ as a vehicle for explosives.

2018年6月8日 · Chrysophyta (krəsŏf´ətə), phylum (division) of unicellular marine or freshwater organisms of the kingdom Protista [1] consisting of the diatoms [2] (class Bacillariophyceae), the golden, or golden-brown, algae (class Chrysophyceae), and the yellow-green algae [3] (class Xanthophyceae).

A small particle feeder that feeds in near-surface coastal waters, generates water currents by the slow swimming movements of antennae and maxillipeds and captures food particles in laminar flow fields. Omnivorous, with diet including wide range of minute unicellular phytoplankton such as diatoms, dinoflagellates, ciliates, and tintinnids.

pennate diatom A diatom (Bacillariophyta) that has bilateral symmetry. Source for information on pennate diatom: A Dictionary of Plant Sciences dictionary.

2018年6月27日 · At this point, the diatom produces gametes that fuse with gametes from other diatoms to produce zygotes. The zygotes develop into full sized diatoms that can begin asexual reproduction once more. When diatoms die, their shells fall to the bottom of the ocean and form deposits called diatomaceous earth. These deposits can be collected and used ...

2018年5月21日 · The amoeba, for example, is capable of detecting chemicals given off by potential food particles such as diatoms, algae, bacteria, or other protozoa. As the cell wall has no definite shape, the cytoplasm can extrude to form pseudopodia (Greek: pseudes , false; pous , foot) in various sizes and at any point of the cell surface.